How Do Probiotics Boost Immunity?

Probiotics are beneficial bacteria or yeast to increase the number of healthy bacteria in the gut. Healthy bacteria in the gut are needed to assist with digestion of food. However, the number of healthy or "friendly" bacteria can decline as a result of antibiotics, diarrhea or sickness indicating the need for replacement of lost bacteria. A healthy gut plentiful in friendly bacteria is beneficial for boosting immunity a now serves a role in prevention and not only treatment.

Integrity of Mucosal Barrier

One way probiotics boost immunity is in improving the integrity of the mucosal barrier. The mucosal barrier is the lining of the stomach and is permeable to many nutrients as well as toxins ingested. Therefore, it is imperative the barrier remain strong and effective in order to prevent toxic substances from crossing into the stomach while allow much needed nutrients to cross. Seventy percent of our immune system function occurs in the gut, according to the UC Berkeley College of Natural Resources. Probiotics work by promoting the integrity of the mucosal barrier and acts as a barrier to toxins and harmful bacteria.

Establishing Good Organisms

Probiotics help to establish colonies of good organisms. When millions of healthy bacteria exist in the gut harmful organisms are discouraged, according to "Today's Dietitian." Growth of bad bacteria is inhibited if there is already a tremendous number of good bacteria present. Millions of healthy bacteria steal the food the bad bacteria need reducing the spread of harmful bacteria.

Alter Immune Cells

Research is growing in the area of the role of probiotics in immune health. Studies are beginning to show that probiotics can alter immune cells in positive ways and strengthening immunity. A study in the August 2010 "Clinical and Experimental Biology" journal reports a white blood cell known as a natural killer cell is of interest in immunity and probiotics. This natural killer cell is responsible for the rejection of tumor cells and cells infected with viruses. This study notes that Lacobacillus casei Shirota, a particular probiotic bacteria, increases the activity of this natural killer cell.

Healthy Stay Healthy

Another way probiotics affect immunity is by helping people who are healthy to stay healthy. "Today's Dietitian" explains the research is growing in support of preventing sickness. For example, children in day centers aren't getting sick as often if they are taking probiotics. Less sick leave is reported in workers who take probiotics, according to a November 2005 study in the "Environmental Health" journal.